STUDY OF THE VARIABILITY OF PEA RESPONSE TO TRANSFORMATION WITH AGROBACTERIUM-TUMEFACIENS AND AGROBACTERIUM-RHIZOGENES STRAINS

The work is devoted to studying the pea interspecies variability of ca pacity to be transformed by A. tumefaciens and A. rhizogenes strains. Transformation experiments were accomplished on inbred lines from gene tic collection of All-Russian Research Institute for Agricultural Micr obiology, as well as on unable to nodulation mutant lines (Nod- sym 5 and sym 8) and their parental Sparkle variety. Axenic seedlings, stem and leaf explants of different genetic forms were inoculated with bact erial suspension; tumor- and rootformation in inoculation sites were a ssessed visually 40 days after inoculation by comparison with control plants and explants. The variability of pea susceptibility to transfor mation was observed. The line 32/11 with highest ability for both tran sformation and regeneration was revealed; the possible connection betw een these processes is discussed. The genetic forms with untypical gen etic response to inoculation with Agrobacterium strains were revealed: for example, those forming roots instead of undifferentiated tumors w hen transformed with A. tumefaciens wildtype strains or, vice versa, f orming tumors when transformed with A. rhizogenes. The variability of phenotypic characters of pea tissues transformed with certain Agrobact erium strains reflects the variability of pea hormone balances and hor mone susceptibilities. The direct connection between nodulation and tr ansformation capacities was not revealed, but the phenotypic effects o f mutants Nod- and the parental variety transformation makes it possib le to discuss the peculiarities of hormone status of these forms. The strain-specifity of transformation and its dependance on plant genotyp e-bacterial strain combination was demonstrated.